A Computational Study of Reductive Elimination Reactions to Form C−H Bonds from Pt(II) and Pt(IV) Centers. Why Does Ligand Loss Precede Reductive Elimination from Six-Coordinate but Not Four-Coordinate Platinum?

摘要: In agreement with the experimental results of Halpern on (PPh3)2Pt(CH3)H, B3LYP and CCSD(T) calculations model species (PH3)2Pt(CH3)H (1) find that reductive elimination methane from this four-coordinate, Pt(II) complex proceeds without prior PH3 ligand loss. The free energy activation calculated for 1 is in good value measured (PPh3)2Pt(CH3)H. contrast to case 1, we were unable a genuine pathway direct methane, concomitant loss, (PH3)2Cl2Pt(CH3)H (13). This computational finding accord observation eliminations six-coordinate, Pt(IV) complexes almost invariably take place via involving loss ligand, step. found lower barrier by slightly more than complexes. However, our indicate that...